Continuous printing device



Dec. 22, 1959 D. E. WILLIAMSON CONTINUOUS PRINTING DEVICE Filed May 11,1955 [nae/afar Jailed M'lkzimsam gym/ uoK/wwvu W7 flit" a.

United States Patent CONTINUOUS PRINTING DEVICE Donald E. Williamson,West Concord, Mass., assignor, by mesne assignments, to KalvarCorporation, New Orleans, La., a corporation of Louisiana ApplicationMay 11, 1955, Serial No. 507,633

1 Claim. (CI. 95-75) The photographic technique that provides records interms of areas consisting of a microdispersed, multiphasic scatteringsystem (also known under the name of vesicular, bubble or scatterphotography), utilizes photographic material which comprises a vehicle(on a suitable support or self-supporting) and therein a light sensitiveagent which upon irradiation generates gas; diazo compounds whichliberate nitrogen when exposed to light, are at the present timepreferred for this purpose. The vehicle can be a specially compoundedgelatin or synthetic. The light for exposing such material to anoriginal or intermediate copy has to be fairly strong and should notconsiderably raise the temperature of the photographic copying stock.Upon exposure, this photographic material is subjected to a treatmentwhich is usually referred to as development, in analogy withconventional photographic techniques, and which involves the raising ofits temperature to a few hundred degrees.

Some of the objects of the present invention are to provide a continuousprinting device which carries out the above mentioned steps of exposureand development rapidly, exactly, and conveniently, and in accordancewith the basic principles that are essential for this type ofphotography, especially without subjecting the photographic stock toundue heating during exposure, to provide such a device which carriesout the exposure as rapidly as possible with the light sources availableat the present time, to provide apparatus of this type which carries outthe exposure and developing steps automatica-lly, requiring a minimum ofeffort and thought from the operator, to provide an exposure devicewhich can be utilized within continuous printing apparatus according tothe present invention or separately, when it provides advantages notheretofore obtained, to provide-a heat developing device which can beutilized within continuous printing apparatus according to the presentinvention, but is also suited for use with other exposure devices, toprovide apparatus of the above indicated type which is of optimumoperational simplicity and reliability permitting the passing of thephotographic stock and of a sheet to be copied, through the exposure anddeveloping components to obtain a completed copy without intermediatehandling of the material, and without requiring manual peeling of theoriginal from the copying stock, and generally to provide an improveddevice of the above indicated type.

In summary, the substance of the main aspects of the invention is asfollows.

According to the invention, apparatus for the exposure and heatdevelopment of photographic records comprises a drum mounted forrotatory movement; in close contact with the drum a translucent beltmoving with the drum tov form an exposure nip region parallel to theaxis of rotation of the drum, for holding photographic material thatmoves with the drum and the belt; a light source essentially coveringthe nip region for exposure of the material; heat development meansextending along the discharging side of the exposure nip region, whichPatented Dec. 22, 1959 development means includes a roller and a curvedheating platen contacting the roller to form a development nip regionessentially parallel to the exposure nip region; means for directing theexposed photographic material from the discharging side of the exposurenip region into the adjacent receiving side of the development nipregion; and means for driving the drum and the roller at essentially thesame circumferential speed.

According to another aspect of the invention, photographic exposuremeans are provided which comprise a rotatably supported exposure drum; aplurality of belt transport rolls supported for rotation on axesparallel to the drum and essentially on one side of the drum; an endlesstranslucent belt wound around the drum and the rolls to form a nipregion at the side of the rolls; a light box lined with reflectingmaterial, containing an extended light source and opening towards thenip region to cover an appreciable portion thereof with radiation fromthe light source; and means for driving the drum and the belt. In apractically important aspect, the light box is subdivided into twoportions parallel to the nip region, by means of a heat absorbing orreflecting plate, the portion towards the nip region having wallsreaching close to that region and the other portion being reflecting andcontaining the lamp; one end of the box is open and on the other side isa chest supplied with cooling air that passes into both portions coolingthem separately and discharging through the open end of the box.

According to yet another aspect of the invention, heat development meansare provided which comprise a driven roller covered with resilientfriction material such as for example felt; and a platen, heated to anadjustable temperature and concavely curved around the roll to form aheat development nip where photographic material is moved past theheated platen in firm contact therewith; the nip region of the platen ispolished so that the friction covering of the driven roller will movethe material therethrough.

The following description of a typical embodiment illustrates these andother objects, and aspects of the nature of the invention. Thisdescription refers to a drawing in which Fig. 1 is a front elevation ofthe embodiment herein described;

Fig. 2 is a rear elevation of the upper portion of the device shown inFig. 1, with the lower frame portion omitted;

Fig. 3 is a side elevation seen from the right-hand or drive side ofFig. 1; and

Fig. 4 is a schematic cross section through the device illustrating itsessential components and their operation.

This practical embodiment of a device according to the invention has thefollowing principal components, namely an exposure nip Ne defined by adrum 11 and a transparent exposure belt 12 of the endless type, a set 14of four transport rolls 14.1, 14.2, 14.3, and 14.4, which hold the belt12 in tension against the cylinder 11, a light box 15, a developer nipNd defined by a roller 41 and a platen 45, and a frame structure 17mounted on a convenient base 18 and carrying the above enumeratedcomponents and various auxiliary devices, all of which will now bedescribed in detail.

The exposure drum 11 is made of metal such as alumi num and it isidlingly pivoted on the frame portions 17.1, 17.2. The transport rolls,made from aluminum tubing, are similarly supported on frame plates 17.1,17.2 and one of them, such as roll 14.1, is driven as will be explainedhereinbelow. The translucent or transparent belt 12 is applied aroundthe outside of the four rollers 12 and concavely over the'periphery ofdrum 1'1 adjacent to the rolls 14, as clearly indicated in Fig. 4.

'the lamp 27 (Fig. 3).

reflecting or absorbing material 33 which provides two -longitudinalcompartments 26 and 31 both of which can be cooled by streams of air aswill be described hereinbelow. The lamp housing proper, 26, has wallswhich are coated with suitable reflecting material or carry -mountedthereon reflector plates 26.1, 26.2 forming an angle in which is mounteda tubular high emission lamp 27 of the gaseous discharge type, by meansof brackets 28, one on each of the frame plates 17, as shown in Fig. 3.These brackets carry the terminal clips 29 for On the other side ofplate 33 is the second light box portion 31 with reflecting deflectorwalls 31.1, 31.2 reaching close towards the nip Ne to direct the lightfrom the lamp 27 and from the reflectors 26 towards the exposure face ofdrum 11 and belt 12.

The transport roller 41 of the developing unit is made of aluminumtubing similar to the above described transport rolls 14, and it iscovered with felt or similar material, indicated at 42, which materialis resilient enough to cause its surface to make contact with the curvedplaten 45 at the developer nip region Nd, such as to press thephoto-graphic material against the platen when the material is fedthrough the device as will be described below. The platen 45 ispolished, and heated by means of a heating element of conventionaldesign within the casing 47, the temperature of which is regulated by aconventional thermostat 49.

The heater casing 47 also carries a sheet directing device 51 consistingessentially of a strip 51.1 and clips 51.2 screwed thereto as indicatedin Figs. 1, 3 and 4. It will be noted that the discharging end of nip Neis located adjacent to the lower edge 51 of the developer casing and tothe receiving end of the developer nip Nd; these components are soarranged that the exposed photographic stock is securely guided into thedeveloper nip.

The above mentioned auxiliary equipment includes the following principalcomponents.

A motor 71 drives, through a conventional torque convertor 72, a chainsprocket 73 whose chain 75 drives the sprocket 76 of the developerroller 41 with its felt cover 42. The chain 75 also drives the belt roll14.1, advancing the belt 12 on the rolls 14. This drive is so arrangedthat drum 11 and belt 12, forming the exposure nip Ne, and the developerroller 41 forming with the platen 45 the developer nip Nd, move at thesame circumferential speed.

The tubular lamp 27 of the high intensity gas discharge type, issupplied through terminal clips 29, by means of transformer 81 andcapacitor 82, in well known manner.

A blower 85, driven by electric motor 86, discharges into a chamber 87,mounted on the frame panel 17.1 as indicated in Figs. 1 and 2. Asmentioned above, the air blown into chamber 87 is discharged through thetwo compartments 26 and 31 of the light box 15, emerging on the side ofpanel 17.2 as indicated in Fig. 3.

An arrangement for tightening the belt 12 by means of one of the rollsis indicated in Fig. 3. This arrangement includes two springs 14.8,14.9, attached at one end to the frame and attached on the other end tothe sliding bearings of roll 14.4, which run in slots 17.8 and 17.9 ofplates 17.1 and 17.2.

The roller 41 as well as the drum 11 and the belt 12 are of sufiicientlength to accommodate the maximum size of the photographic materialwhich is to be handled. As mentioned above, the roll 41 is covered withfelt or similar material 42 which material is resilient enough to causeits surface to make contact with the heated platen 45 and to press thephotographic material against the platen when it is fed through thedeveloper. The friction between the layer 42 and the photographic sheetsis sufliciently high as compared to that between the sheets and thepolished platen 45, such as to carry the sheets securely through thedeveloper nip.

The above described device operates as follows.

Prior to printing, the lamp 27 is started in well known manner. Exposuredrum 11 with belt 12, and developer roller 41 are set into motion bystarting motor 71 and setting the desired speed by means of drive 72;this speed will depend upon the photographic characteristics of theoriginal and of the copying stock, and upon the type of the lamp 27. Theblower is started in order to provide cooling air for the light box 15.Current is supplied to heater 47, thermostat 49 being set to maintainthe temperature that is most favorable for the technique in question,which again depends upon the type of original and copying stock used andalso upon the emission intensity and quality of the lamp 27. About 200F. is a frequently used temperature.

The sheet to be copied, indicated at O of Fig. 4, and the printing stockindicated at S of the same figure are fed into the exposure nip Ne. Theyproceed together between the drum and the belt, past the light box 15 asbounded by walls 31.1 and 31.2. The tension provided by the devicedescribed above with reference to the springs 14.8, 14.9 as applied toroller 14.4, keeps the belt 12 taut and in tension against the cylinder,securing good contact between the two sheets along the nip Ne. Thephotographic stock is exposed without its temperature beingsubstantially raised, due to the cooling air forced through thecompartments 26 and 31, as above described. The air forced throughchannel 26 mainly carries off heat from the lamp, whereas the airflowing through channel 31 cools the material in the nip. The heatabsorbing material of plate 33 assists in this respect.

After the proper exposure time, regulated as mentioned above, the twosheets now emerge from nip Ne, and are passed above the guide 51 intothe developer nip Nd between the polished platen 45 and the developingroller 41. As above described, the developer roller 41 is driven at acircumferential speed equal to that of the belt 12 so that the sheetsproceed smoothly through the device. The completed print P and theorig'nal O are then discharged, as indicated in Fig. 4. The diameter ofthe developing roller 41 is chosen to provide, with the givencircumferential speed, an optimum development time. It will be evidentthat exposed photographic stock alone can be treated in the developernip, if desired.

It should be understood that the present disclosure is for the purposeof illustration only and that this invention includes all modificationsand equivalents which fall within the scope of the appended claim.

I claim:

Apparatus for the exposure and heat development of photographic records,comprising: a drum mounted for rotary movement; a plurality of transportrolls supported for rotation on axes parallel to, and essentially on oneside of said drum; an endless translucent belt wound on said drum andsaid rolls to form an exposure nip region on the side of said rolls; alight box including an elongate lamp and a reflector extending alongsaid exposure nip region for the irradiation of photographic materialbetween said drum and said belt at said region; means between said lightsource and said drum and belt for blocking heat radiations while passingexposure light heat development means extending along the dischargingside of said exposure nip region, including a roller covered withresilient friction material and mounted parallel to said drum for rotarymovement, a curved polished platen contacting said roller to form adevelopment nip region essentially parallel to and adjacent to saiddischarging side of said exposure nip region, and means for heating saidplaten; means for directing exposed photographic mater al from saiddischarging side of the exposure nip region References Cited in the fileof this patent UNITED STATES PATENTS 744,039 Brown Nov. 17, 1903 8Dalton Oct. 25, 1910 Thornton Apr. 24, 1917 Sheppard Oct. 9, 1934 BuskesJune 6, 1950 Shore Sept. 19, 1950 Codichini et al Feb. 8, 1955 HerrickMar. 8, 1955 Fairbanks July 2, 1957

